阅读说明：本技术 一种基于银纳米线的复合电极及其制备方法 (Silver nanowire-based composite electrode and preparation method thereof ) 是由 刘本艳 于 2021-09-16 设计创作，主要内容包括：本发明提供了一种基于银纳米线的复合电极及其制备方法,包括聚二甲基硅氧烷PDMS基底、银纳米线Ag NW导电层和导线丝网,以及导电的碳纳米管CNT-aPDMS粘贴层,银纳米线Ag NW导电层附着在二甲基硅氧烷PDMS基底上,银纳米线Ag NW导电层上绕制有导线丝网,导线丝网上涂覆有碳纳米管CNT-aPDMS粘贴层。本发明制备的基于Ag NW的复合电极,其表面的CNT-aPDMS层具有aPDMS的粘性,而且由于填充了CNT,也具有导电性,使得复合电极可以直接粘贴在皮肤上；由于aPDMS具有生物相容性,不会伤害皮肤,可长期使用。Ag NW导电层的导电性好,相当于导体,Ag NW层的存在大大提高了复合电极的导电性能,利于生理电信号的采集；嵌入的导线丝细,可以隐藏于电极内部,不增加电极面积,有利于外接电路设备。(The invention provides a silver nanowire-based composite electrode and a preparation method thereof. According to the Ag NW-based composite electrode prepared by the invention, the CNT-aPDMS layer on the surface has the viscosity of aPDMS, and the CNT is filled with CNT and also has conductivity, so that the composite electrode can be directly pasted on skin; because aPDMS has biocompatibility, it will not harm skin, and can be used for a long time. The Ag NW conducting layer has good conductivity, is equivalent to a conductor, and the existence of the Ag NW layer greatly improves the conductivity of the composite electrode, thereby being beneficial to the collection of physiological electric signals; the embedded wire is thin and can be hidden in the electrode, the area of the electrode is not increased, and the embedded wire is beneficial to external circuit equipment.)

1. A silver nanowire-based composite electrode is characterized in that: the conductive wire mesh is wound on the silver nanowire Ag NW conductive layer, and the carbon nanotube CNT-aPDMS bonding layer is coated on the conductive wire mesh.

2. A preparation method of a silver nanowire-based composite electrode is characterized by comprising the following steps: the method comprises the following steps:

step (1), preparing a silver nanowire conducting layer:

curing a thin layer of polydimethylsiloxane PDMS on the glass substrate; sucking the silver nanowire Ag NW dispersion liquid by using a dropper, fully dripping a microporous filter membrane, drying, turning over the filter membrane, enabling one surface of the silver nanowire to face downwards, and attaching the silver nanowire onto PDMS; covering a glass slide on the filter membrane, applying pressure, transferring the Ag NW onto the PDMS, and putting the PDMS into an oven for curing; after curing, the filter membrane is peeled off to prepare a PDMS layer attached with an Ag NW conducting layer;

step (2), preparing a CNT-aPDMS mixture:

mixing carbon nanotube powder with ethanol, and performing ultrasonic treatment to obtain CNT dispersion; adding the aPDMS A component into the CNT dispersion liquid, magnetically stirring, and then putting into a vacuum drying oven to evaporate the solvent; adding the aPDMS B component, and uniformly stirring to obtain a CNT-aPDMS mixture;

step (3), preparation of Ag NW-based composite electrode:

and winding a conducting wire on the surface of the Ag NW conducting layer, coating a CNT-aPDMS mixture on the conducting wire, scraping the surface by using a glass slide, and curing in an oven to obtain the silver nanowire-based composite electrode.

3. The method for preparing the silver nanowire-based composite electrode according to claim 2, wherein the method comprises the following steps: in the step (1), according to the weight ratio of polydimethylsiloxane PDMS monomer: PDMS is prepared according to the proportion of 10:1, evenly stirred, vacuumized and de-bubbled, and then dropped on a glass substrate, kept stand for 10min, placed on a hot plate, heated at 50 ℃ for 15 min.

4. The method for preparing the silver nanowire-based composite electrode according to claim 2, wherein the method comprises the following steps: the microporous filter membrane in the step (1) is a mixed fiber filter membrane, and the pore size is 0.22-1.2 microns.

5. The method for preparing the silver nanowire-based composite electrode according to claim 2, wherein the method comprises the following steps: the aPDMS in the step (2) is a flexible skin adhesive and is a two-component elastic silicone rubber adhesive.

6. The method for preparing the silver nanowire-based composite electrode according to claim 2, wherein the method comprises the following steps: the ratio of the CNT to the aPDMS in the step (2) is 2-4%.

7. The method for preparing the silver nanowire-based composite electrode according to claim 2, wherein the method comprises the following steps: the conducting wire in the step (3) is a tinned copper wire with the diameter of 0.05 mm.

8. An electrode, characterized in that it is prepared by the method for preparing a silver nanowire-based composite electrode according to claims 1 to 7.

Technical Field

The invention relates to the technical field of composite electrodes, in particular to a silver nanowire-based composite electrode and a preparation method thereof.

Background

Cardiovascular diseases are one of the main diseases threatening human life, and electrocardiosignals are bioelectricity signals generated by exciting cardiac muscles when the heart is active, so that electrocardiographic examination has great significance for detecting and diagnosing heart diseases. At present, the wet electrode is commonly used in medicine for collecting electrocardiosignals. Wet electrodes are often used in conjunction with conductive gel to reduce the contact impedance between the electrode and the skin. The conductive adhesive is easy to evaporate and dry, so that the electrocardiosignals are attenuated, and long-term monitoring of the electrocardiosignals is not facilitated. Therefore, the dry electrode becomes a better choice for long-term monitoring of electrocardiosignals. Among them, the flexible dry electrode is more and more favored in wearable medical devices because it is soft and does not irritate the skin, and can be used for a long time.

The Chinese patent with the application number of 201510168806.6 provides an electrocardioelectrode and a preparation method thereof, wherein the method comprises the steps of depositing a graphene nanowall on a metal sheet, transferring the graphene nanowall onto a flexible substrate, and finally removing the metal sheet to obtain the graphene nanowall flexible electrocardioelectrode. The electrode prepared by the method is low in impedance and good in conductivity, but graphene cannot be directly adhered to skin, other tools are needed, and the electrode and the skin are easy to generate relative displacement during movement, so that stable acquisition of electrocardiosignals is influenced. And the deposition process in preparation requires the assistance of expensive equipment. Therefore, an electrocardio-electrode which has a simple and feasible preparation method and can be adhered to the skin automatically is needed.

Disclosure of Invention

The invention aims to provide a silver nanowire-based composite electrode and a preparation method thereof.

According to an object of the present invention, the present invention provides a silver nanowire-based composite electrode, which comprises a polydimethylsiloxane PDMS substrate, a silver nanowire Ag NW conductive layer and a wire mesh, wherein the silver nanowire Ag NW conductive layer is attached to the polydimethylsiloxane PDMS substrate, the wire mesh is wound on the silver nanowire Ag NW conductive layer, and a conductive carbon nanotube CNT-aPDMS adhesive layer is coated on the wire mesh.

According to another object of the present invention, the present invention provides a method for preparing a silver nanowire-based composite electrode, comprising the steps of:

step (1), preparing a silver nanowire conducting layer:

curing a thin layer of polydimethylsiloxane PDMS on the glass substrate; sucking the silver nanowire Ag NW dispersion liquid by using a dropper, fully dripping a microporous filter membrane, drying, turning over the filter membrane, enabling one surface of the silver nanowire to face downwards, and attaching the silver nanowire onto PDMS; covering a glass slide on the filter membrane, applying pressure, transferring the Ag NW onto the PDMS, and putting the PDMS into an oven for curing; after curing, the filter membrane is peeled off to prepare a PDMS layer attached with an Ag NW conducting layer;

step (2), preparing a CNT-aPDMS mixture:

mixing carbon nanotube powder with ethanol, and performing ultrasonic treatment to obtain CNT dispersion; adding the aPDMS A component into the CNT dispersion liquid, magnetically stirring, and then putting into a vacuum drying oven to evaporate the solvent; adding the aPDMS B component, and uniformly stirring to obtain a CNT-aPDMS mixture;

step (3), preparation of Ag NW-based composite electrode:

and winding a conducting wire on the surface of the Ag NW conducting layer, coating a CNT-aPDMS mixture on the conducting wire, scraping the surface by using a glass slide, and curing in an oven to obtain the silver nanowire-based composite electrode.

Further, in step (1), according to the weight ratio of polydimethylsiloxane PDMS monomer: PDMS is prepared according to the proportion of 10:1, evenly stirred, vacuumized and de-bubbled, and then dropped on a glass substrate, kept stand for 10min, placed on a hot plate, heated at 50 ℃ for 15 min.

Further, the microporous filter membrane in the step (1) is a mixed fiber filter membrane, and the pore size is 0.22-1.2 microns.

Further, the aPDMS in the step (2) is a flexible skin adhesive, and is a two-component elastic silicone rubber adhesive.

Further, the ratio of the CNT to the aPDMS in the step (2) is 2% -4%.

Further, the conducting wire in the step (3) is a tinned copper wire with the diameter of 0.05 mm.

An electrode is prepared by adopting the preparation method of the silver nanowire-based composite electrode.

Advantageous effects

According to the Ag NW-based composite electrode prepared by the invention, the CNT-aPDMS layer on the surface has the viscosity of aPDMS, and the CNT is filled with CNT and also has conductivity, so that the composite electrode can be directly pasted on skin; because aPDMS has biocompatibility, it will not harm skin, and can be used for a long time. The Ag NW conducting layer has good conductivity, is equivalent to a conductor, and the existence of the Ag NW layer greatly improves the conductivity of the composite electrode, thereby being beneficial to the collection of physiological electric signals; the embedded wire is thin and can be hidden in the electrode, the area of the electrode is not increased, and the embedded wire is beneficial to external circuit equipment.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic illustration of the dispersion of droplets onto a microfiltration membrane according to an embodiment of the invention;

FIG. 2 is a schematic view of a glass substrate and PDMS according to an embodiment of the present invention;

FIG. 3 is a schematic view of a cover slip on a filter according to an embodiment of the present invention;

FIG. 4 is a schematic view of a microporous filter membrane and PDMS according to an embodiment of the present invention;

fig. 5 is a structural view of a composite electrode of silver nanowires according to an embodiment of the present invention;

fig. 6 is another structural view of a composite electrode of silver nanowires according to an embodiment of the present invention;

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. Furthermore, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

A silver nanowire-based composite electrode comprises a Polydimethylsiloxane (PDMS) substrate, a silver nanowire Ag NW conducting layer, a wire mesh and a conductive carbon nanotube CNT-aPDMS adhesive layer, wherein the silver nanowire Ag NW conducting layer is attached to the PDMS substrate, the wire mesh is wound on the silver nanowire Ag NW conducting layer, and the wire mesh is coated with the carbon nanotube CNT-aPDMS adhesive layer.

Example 2

A composite electrode based on silver nanowires and a preparation method thereof comprise the following steps:

(1) dripping polydimethylsiloxane PDMS on a glass substrate, placing the glass substrate on a hot plate, and heating and curing;

(2) sucking the Ag NW dispersion liquid by a dropper, dripping the Ag NW dispersion liquid on a microporous filter membrane, and repeatedly operating for several times to enable the Ag NW to be paved on the filter membrane;

(3) after the filter membrane is dried, turning over the filter membrane, enabling the Ag NW layer to face downwards, and attaching the filter membrane to the PDMS in the step (1);

(4) cover the filter with a glass slide, press the slide with pressure, transfer the Ag NW onto PDMS;

(5) after drying in an oven, stripping the filter membrane to prepare a PDMS substrate attached with the Ag NW conducting layer;

(6) mixing CNT and ethanol and performing ultrasonic treatment to prepare CNT dispersion liquid;

(7) adding the aPDMS A component into the CNT dispersion liquid, uniformly stirring by magnetic force, and putting the CNT dispersion liquid into a vacuum drying oven to evaporate redundant ethanol;

(8) adding the aPDMS B component into the mixture of the CNT-aPDMS A component, and uniformly stirring to obtain a CNT-aPDMS mixture;

(9) winding a wire on the Ag NW conducting layer in the step (5), coating a CNT-aPDMS mixture on the wire, and scraping the surface by using a glass slide, wherein the wire is embedded into the wire without being exposed;

(10) and (5) placing the composite electrode into an oven, and curing to obtain the Ag NW-based composite electrode.

Example 3

The preparation process of the silver nanowire Ag NW conductive layer is shown in fig. 1-4, and comprises the following steps:

(1) according to the polydimethylsiloxane PDMS monomer: preparing PDMS according to the proportion of 10:1, stirring uniformly, vacuumizing to remove bubbles, dripping on a glass substrate, standing for 10min, placing on a hot plate, heating at 50 deg.C for 15 min;

(2) sucking the Ag NW dispersion with a dropper, dropping on a microporous filter membrane with a diameter of 25mm, sucking the liquid with filter paper, retaining the Ag NW on the filter membrane, and continuing the operation until the Ag NW is spread over the filter membrane (see FIG. 1);

(3) turning over the filter membrane adsorbed with the Ag NW, and flatly placing the filter membrane on the PDMS in the step (1), as shown in FIG. 2;

(4) cover the filter with a glass slide and press the slide with pressure to transfer the Ag NWs on the filter to the PDMS (see figure 3);

(5) after 1h in an oven at 70 ℃, the filter was dried and the filter was peeled off, as shown in fig. 4, to produce a PDMS substrate with an Ag NW conductive layer attached.

Example 4

The preparation method of the CNT-aPDMS mixture comprises the following steps:

mixing CNT and ethanol, and putting into an ultrasonic machine for ultrasonic treatment for 10h to obtain uniform CNT dispersion liquid; adding an aPDMS A component (the mass ratio of A, B components in aPDMS is 1:1 according to the proportion of CNT: aPDMS is 3%), placing on a magnetic stirrer, and heating to 50 ℃ and stirring for 2 h; placing the mixture of the CNT-aPDMS A component into a vacuum drying oven at 100 ℃, and evaporating excessive ethanol; the aPDMS B component is added into the mixture of the CNT-aPDMS A component, and the mixture is stirred uniformly to prepare the CNT-aPDMS mixture.

The CNT is as follows: the percentage of pdms 3% refers to the specific gravity of carbon nanotubes in pdms, i.e. 10 g of pdms corresponds to 0.3 g of CNTs. The invention can also adopt the proportion combination of the CNT and the aPDMS which are 2 to 4 percent, and can meet the performance requirement.

The aPDMS is a flexible skin adhesive, and the Dow Corning flexible skin adhesive is used in the embodiment, and is MG 7-9850 (component A and component B), and the aPDMS is sleeved with the A and B components which are all commonly used in the field and can be directly purchased.

Example 5

The structure of the silver nanowire-based composite electrode is shown in fig. 5 and 6, and comprises a PDMS substrate attached with an Ag NW conductive layer, an embedded wire mesh and a CNT-aPDMS conductive adhesive layer.

The preparation method comprises the following steps:

cutting off redundant PDMS on the PDMS substrate attached with the Ag NW conducting layer, wherein the PDMS and the Ag NW layer have the diameter of 25 mm; fixing the PDMS layer on the glass slide, winding a wire with the diameter of 0.05mm on the PDMS layer, and connecting the wire with external circuit equipment to facilitate testing; coating the CNT-aPDMS mixture on an Ag NW conducting layer, covering a wire mesh, and scraping the surface by using a glass slide; and putting the whole structure into an oven at 120 ℃ for 5h, and twisting the wire into a strand after the CNT-aPDMS layer is completely cured to obtain the Ag NW-based composite electrode.

According to the Ag NW-based composite electrode prepared by the invention, the CNT-aPDMS layer on the surface has the viscosity of aPDMS, and the CNT is filled with CNT and also has conductivity, so that the composite electrode can be directly pasted on skin; because aPDMS has biocompatibility, it will not harm skin, and can be used for a long time. The Ag NW conducting layer has good conductivity, is equivalent to a conductor, and the existence of the Ag NW layer greatly improves the conductivity of the composite electrode, thereby being beneficial to the collection of physiological electric signals; the embedded wire is thin and can be hidden in the electrode, the area of the electrode is not increased, and the embedded wire is beneficial to external circuit equipment.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.